EP0247156B1 - Polychelierende stoffe für abbildung- und spektralerhöhung (und spektrale verschiebung) - Google Patents

Polychelierende stoffe für abbildung- und spektralerhöhung (und spektrale verschiebung) Download PDF

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EP0247156B1
EP0247156B1 EP86907195A EP86907195A EP0247156B1 EP 0247156 B1 EP0247156 B1 EP 0247156B1 EP 86907195 A EP86907195 A EP 86907195A EP 86907195 A EP86907195 A EP 86907195A EP 0247156 B1 EP0247156 B1 EP 0247156B1
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dtpa
image
agent
dextran
enhancing agent
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EP0247156A1 (de
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David F. Ranney
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Abeona Therapeutics Inc
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Access Pharmaceuticals Inc
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00—Preparations for testing in vivo
    • A61K49/06—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations
    • A61K49/08—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by the carrier
    • A61K49/10—Organic compounds
    • A61K49/12—Macromolecular compounds
    • A61K49/126—Linear polymers, e.g. dextran, inulin, PEG
    • A61K49/128—Linear polymers, e.g. dextran, inulin, PEG comprising multiple complex or complex-forming groups, being either part of the linear polymeric backbone or being pending groups covalently linked to the linear polymeric backbone
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00—Preparations for testing in vivo
    • A61K49/06—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations
    • A61K49/08—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by the carrier
    • A61K49/085—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by the carrier conjugated systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00—Preparations for testing in vivo
    • A61K49/06—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations
    • A61K49/18—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes
    • A61K49/1818—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K51/00—Preparations containing radioactive substances for use in therapy or testing in vivo
    • A61K51/02—Preparations containing radioactive substances for use in therapy or testing in vivo characterised by the carrier, i.e. characterised by the agent or material covalently linked or complexing the radioactive nucleus
    • A61K51/04—Organic compounds
    • A61K51/06—Macromolecular compounds, carriers being organic macromolecular compounds, i.e. organic oligomeric, polymeric, dendrimeric molecules
    • A61K51/065—Macromolecular compounds, carriers being organic macromolecular compounds, i.e. organic oligomeric, polymeric, dendrimeric molecules conjugates with carriers being macromolecules
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K51/00—Preparations containing radioactive substances for use in therapy or testing in vivo
    • A61K51/12—Preparations containing radioactive substances for use in therapy or testing in vivo characterised by a special physical form, e.g. emulsion, microcapsules, liposomes, characterized by a special physical form, e.g. emulsions, dispersions, microcapsules
    • A61K51/1241—Preparations containing radioactive substances for use in therapy or testing in vivo characterised by a special physical form, e.g. emulsion, microcapsules, liposomes, characterized by a special physical form, e.g. emulsions, dispersions, microcapsules particles, powders, lyophilizates, adsorbates, e.g. polymers or resins for adsorption or ion-exchange resins
    • A61K51/1255—Granulates, agglomerates, microspheres
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K2123/00—Preparations for testing in vivo

Definitions

  • the present invention relates to image-enhancing agents, contrast agents or spectral shift agents to enhance tissue or organ images or nuclear spectra obtained from live animals with ultrasound imaging radioisotope scanning or NMR imaging or spectroscopy.
  • radioisotopes preferably emit gamma particles and are generally isotopes of metallic elements.
  • One problem common to the diagnostic usage of such gamma particle-emitting radioisotopes concerns the localization of these materials at sites of particular interest rather than to have them randomly dispersed or rapidly excreted, by the kidney, for example.
  • radioisotope mediated imaging concerns optimizing the circulating half-life of radioisotopes, for example, by preventing or accentuating their binding to serum proteins (e.g., albumin), or by prior conjugation (complexation) to polymeric carriers or receptor-binding substances.
  • serum proteins e.g., albumin
  • a second class of internal body imaging which is undergoing a rapid growth in clinical use is ultrasound imaging. This is based on the detection of differences in the internal velocity (reflectivity) of directed, high-frequency sound waves. Differences in image brightness are produced at the interfaces between tissues with different native densities and ultrasound reflectivities.
  • a present clinical problem is the difficulty of visualizing lesions in the stomach, small and large bowel, bladder, and cavities of the female reproductive tract, due to similarities of ultrasound velocity between these organs of interest and immediately adjacent tissues. Diagnostic introduction of a dense, nonradioactive metal element or ion at sufficient concentrations can confer the significant differences in ultrasound reflectivity which are required to visualize otherwise undetectable tumors and inflammatory lesions.
  • MRI Clinical magnetic resonance Imaging
  • MRI is a rapidly growing, new form of brain and body imaging.
  • Low-field (proton) MRI detects chemical parameters in the immediate environment around the protons of body tissues (predominantly water protons because of their relative abundance). Changes in these parameters occur very early in disease and are independent of physical densities detected by ionizing radiation.
  • MRI has allowed detection of tumors at an earlier clinical stage and with fewer imaging artifacts than is possible with computerized axial tomography (CAT) [Runge et al., (1983) Am. J. Radiol V 141, p 1209]. Under optimal conditions, image resolution is in the submillimeter size range.
  • CAT computerized axial tomography
  • Image-enhancing agents enhance tumor masses differently than surrounding edema fluid or abscesses. This allows the extent and invasion of tumors to be defined more precisely. Lesions with infiltrative-type growth (e.g., certain metastatic carcinomas and glioblastomas) will require contrast agents for demarcation between tumor and edema fluid [Felix et al. (1985) Proc. Soc. Mag. Res. Med. V 2, p 831]. 4. Image-enhancing agents improve the distinction between recurrent tumor and fibrous tissue resulting from surgery and radiation. 5.
  • Image-enhancing agents can decrease the time required per scan and potentially decrease the number of scans required per procedure. This increases the volume of procedures and decreases their expense.
  • Body imaging has a significantly lower resolution (typically 0.5-1.0 cm) and sensitivity (decreased signal-to-noise ratio) than brain imaging [Wesbey et al. (1983) Radiology V 149, p 175]. These differences result from the greater inhomogeneity of the magnetic field; the larger radiofrequency coil; unequal phase-pulsing of deep versus shallow nuclei; and motion artefacts produced by respiration, cardiac systole, gastrointestinal peristalsis, and voluntary muscle movement; and 7. Advanced (polymeric and microsphere) forms of contrast agents (see below) appear to be required for the optimal acquisition and interpretation of blood-flow and tissue-perfusion images and related spectral (phase) information.
  • Tissue contrast occurs naturally and is related to variations in the chemical environments around water protons (major contributor) and lipid protons (usually minor). Chemical agents have been used to enhance this natural contrast.
  • the one most widely tested clinically is the paramagnetic metal ion, gadolinium (Gd+3) [Runge et al. (1983) Am. J. Radiol V 141, p 1209 and Weinman et al. (1984) Am. J. Radiol V 142, p 619].
  • T1-weighted enhancement can be achieved by selecting the most favorable Gd dose and rf pulse sequence.
  • Gd has the largest number of unpaired electrons (seven) in its 4f orbital, it has the largest paramagnetic dipole (7.9 Bohr magnetons) and exhibits the greatest paramagnetic relaxivity of any element [Runge et al. (1983) Am. J. Radiol V 141, p 1209 and Weinman et al. (1984) Am. J. Radiol V 142, p 619].
  • Gd has the highest potential of any element for enhancing images.
  • the free form of Gd is quite toxic. This results in part, from precipitation at body pH (as the hydroxide). In order to increase solubility and decrease toxicity, Gd has been chemically chelated by small organic molecules.
  • DTPA diethylenetriamine pentaacetic acid
  • the first formulation of this chelate to undergo extensive clinical testing was developed by Schering AG - Berlex Imaging according to a patent application filed by Gries, Rosenberg and Weinmann [DE-OS 3129906 A 1 (1981)]. It consists of Gd-DTPA which is pH-neutralized and stabilized with the organic base, N-methyl-D-glucamine (meglumine).
  • the Schering-Berlex agent is nearing completion of Phase III clinical testing at selected centers across the United States and abroad.
  • the results of preliminary studies indicate that almost all human brain tumors undergo significant enhancement [Felix et al. (1985) Proc. Soc. Mag. Res. Med. V 2, p 831 and K. Maravilla, personal communication]. These include metastatic carcinomas, meningiomas, gliomas, adenomas and neuromas. Renal tumors are also enhanced satisfactorily [Lanaido et al. (1985) Proc. Soc. Mag. Res. Med. V 2, p 877 and Brasch et al. (1983) Am. J. Radiol. V 141, p 1019].
  • the Schering-Berlex formulation is projected to be available for general clinical use in 1987.
  • Emulsions of insoluble, gadolinium oxide particles have been injected into experimental animals with significant image-enhancing effects on the liver [Burnett et al. (1985) Magnetic Res. Imaging V 3, p 65]. However, these particles are considerably more toxic than any of the preceding materials and are inappropriate for human use. Because of the significant disadvantages of existing MR image contrast agents, the present applicant has formulated improved, second-generation prototype agents with reduced toxicity, increased selectivity of tumor and organ uptake, as well as a significant potential for enhancing blood flow images.
  • NMR image-enhancing agents also referred to herein as NMR contrast agents or MR (magnetic resonance) contrast agents
  • MR contrast agents magnetic resonance contrast agents
  • high-field NMR surface-coil spectroscopy of 1H, 13C, 19F, 23Na, and 31P nuclei in spacially localized tissue volumes is gaining in importance and is starting to be applied experimentally to the noninvasive clinical monitoring of genetic and metabolic disorders; myocardial infarcts and metabolism; brain, liver and tumor metabolism; drug distribution and metabolism; blood flow and tissue perfusion measurements; and temperature monitoring in regional hyperthermia.
  • Gadolinium and related agents can produce characteristic changes in the NMR spectrum of adjacent NMR-susceptible nuclei.
  • the present invention provides a method of making an image-enhancing agent or spectral-enhancing agent, which method comprises covalently coupling a biodegradable, water-soluble polymer comprising repeating hydrophilic monomeric units having amino and/or hydroxyl groups and a chelating agent the functional groups of said chelating agent binding to the reactive groups of the monomeric units of said polymer, said chelating agent being associated with a metal ion, characterized in that the coupling of the water-soluble polymer and the chelating agent is carried out in an aqueous protonating solvent and in that the chelating agent has a formation constant for divalent or trivalent metal cations, at physiological temperature and pH, of at least 108.
  • the chelating agents comprise functional groups bound to an amino, quaternary ammonium or other reactive nitrogen group; hydroxyl; carboxy; sulfhydryl; sulfate or sulfonium group of the monomeric units. These chelating agents have a formation constant for divalent or trivalent metal cations of at least 108 (and typically > 1013) at physiological temperature and pH.
  • the conjugation of chelating groups to the polymer (or to form the copolymer) is carried out under chemical conditions and in a solvent which yields a completely soluble (singlet) form of the carrier and avoids significant contamination by microaggregates.
  • the molar ratio of chelating agent/monomeric unit is preferably between 1/5 and 1/25.
  • the molar ratio of chelating agent/monomeric unit is preferably between 1/5 and 1/25.
  • This image-enhaning agent is biodegradable to intermediary metabolites, rapidly excretable chelates, polymers, oligomers, monomers or combinations thereof, all of which have low toxicity and are cleared overwhelmingly by the renal route.
  • the term "low toxicity” used herein means having little significant toxic effects at usable dosages of the image-enhancing agents.
  • These image-enhancing agents may further comprise a paramagnetic metal, transition element or rare-earth ion for enhancement of the images or spectra arising from induced magnetic resonance signals.
  • a paramagnetic metal, transition element or rare-earth ion for enhancement of the images or spectra arising from induced magnetic resonance signals.
  • metal ions refers to any of these materials as being capable of forming positively charged ions.
  • the polymeric (or microspheres--see below) nature of these agents, is designed to produce a substantial increase in the NMR potency of each paramagnetic metal ion, compared to small metal chelates.
  • Images resulting from scanning of gamma or positron particle emissions may be enhanced when the image-enhancing agent of the present invention comprises a radioisotopic metal, transition element or rare-earth ion (or oxides of the preceding entities) emitting gamma position particles.
  • Images resulting from ultrasound scanning may be enhanced by modifying the native tissue reflectivity (velocity) of high frequency sound waves, when the image-enhancing agent of the present invention comprises one of the relatively dense, nonradioactive metals or metal ions.
  • the initially water-soluble image-enhancing agent produced by the method as described above is converted into a microsphere formed by oil-phase emulsification.
  • the initially water-soluble image-enhancing agent produced by the method as described above is converted into a microaggregate form by ionic (paired-ion) coupling.
  • Images of the internal structures of an animal may be obtained by a wide variety of means known to those skilled in the art.
  • the administration of metal, transition-element and rare-earth containing makers is utilized. These markers, because of the physical properties of their metal components, may be used to enhance the quality of images produced by numerous means.
  • MR magnetic resonance
  • NMR nuclear magnetic resonance
  • the present invention comprises novel ways to entrap metal- or paramagnetic metal-chelate complexes in biodegradable, hydrophilic polymeric microcarriers.
  • the chelate is chemically conjugated in large numbers to hydrophilic polymers such as long-chain dextrans (1-6 linked, soluble, moderately branched polymers of glucose).
  • hydrophilic polymers are biodegradable and water-soluble. They are either synthetic or derived from eukaryotes, procaryotes, hybrid organisms, or plants and comprise repeating hydrophilic monomeric units having amino, hydroxyl or sulfate groups.
  • They may be further derivatized to contain carboxylic acid, sulfonium or sulfhydryl groups; or quaternary ammonium or other reactive nitrogen groups.
  • the negatively charged, naturally occurring, repeating hydroxyl or sulfate groups may contribute to the stabilization of binding of positively charged Gd ions, over and above the stability of binding conferred by the covalently conjugated chelators.
  • the image-enhancing agents of the present invention comprise chelates or chelating agents having functional groups bound to hydroxyl, amino, quaternary ammonium (or other nitrogen functional group), carboxyl, sulfhydryl, sulfonium or sulfate group of the monomeric units of the polymer.
  • These chelating agents are further defined as having formation (stability) constants for divalent or trivalent metal cations of at least 108 and typically greater than 1013 at mammalian physiological pH and temperatures.
  • the whole image-enhancing agents described above are characterized as being biodegradable by mammals to intermediary metabolites or excretable chelates, polymers, oligomers, monomers or combinations thereof, all of which have low toxicity.
  • Chelating agents having the properties described above have then the two basic properties of affinity for divalent or trivalent metals and also the ability to bond to one or more reactive groups as listed 2 paragraphs above, which themselves are bound to the polymer.
  • Particularly preferred chelating agents of the present invention include EDTA (ethylenediaminetetraacetic acid); DTPA (diethylenetriaminepentaacetic acid); TTHA (triethylenetetraaminehexaacetic acid); and DOTA (1,4,7,10-tetraazacyclododecane-N,N',N'',N''' tetraacetic acid).
  • a particularly preferred image-enhancing agent of the present invention comprises dextran polymer and DTPA chelating agent wherein the method of conjugation results in a polymer-chelate which is completely water soluble--e.g. avoids microaggregation--(see below).
  • This particularly preferred agent when in combination with gadolinium has been found to very effectively enhance internal (in vivo) images arising from induced magnetic resonance signals.
  • Alternative elements (ions) for use in MRI could include those of atomic numbers 21 through 29 and 57 through 70, with particular emphasis on numbers 24-29 and 62-69.
  • the polymer of the image-enhancing agents described herein is preferably a polysaccharide or oligosaccharide and most preferably dextran.
  • Polyamino substances poly-L-lysine, for example, are usable but not generally preferred because of their net polymeric (closely spaced) positive charges at a physiological pH, although in conceivable circumstances this type of polymer could be desirable
  • the polymers of the present invention should be biodegradable.
  • biodegradability indicates that internally available mammalian enzymes or conditions lead to the breakdown of the polymer, particularly to an excretable and non-toxic form.
  • non-biodegradable polysaccharides such as cellulose and its water-soluble derivatives are not preferred for the practice of the present invention.
  • Biodegradability may indicate further that mammalian enzymes or conditions lead to cleavage of the chemical bond which attaches the metal chelator to the polymer or to the alternating monomeric units of the copolymer.
  • the polymers of the present invention should have molecular weights of between 1,000 and 2,000,000 daltons.
  • a more preferable size range for most uses is between 40,000 daltons and 75,000 daltons, this range representing a frequent optimum for the hybrid objectives of, amplifying the relaxivity of each Gd, allowing extravasation of an initially intravascular agent, and localization of this agent in tumors and inflammatory lesions, and of slightly-to-moderately delaying or otherwise modifying the renal excretion of these polymeric agents relative to lower molecular weight agents such as Gd:DTPA (dimeglumine).
  • the functional groups of the chelating agents are preferably bound to the monomeric units of the polymer by a covalent linkage, although in certain cases a strong noncovalent bond may be usable.
  • the most preferable covalent bond of chelating agent to polymer is an ester linkage, due to its ease of formation, adequate stability for biological targeting, and optimal susceptibility to enzymatic cleavage for subsequent (post-imaging), clearance of the metal chelates from target cells and from the body.
  • conjugation of chelator groups when performed in the usual, side-chain configuration is preferably carried out according to a one-step method which requires aqueous-phase coupling of the chelator's di-anhydride substrate, at a physiologic pH of less than 8.5, to carrier dextran of the desired molecular size.
  • a carrier size of greater than approximately 10,000 to 20,000 daltons is preferred in order to provide the additional advantage of limiting the agents initial biodistribution almost exclusively to the blood vascular compartment [Grotte (1956) Acta Chirurgica Scandanavia V 211 (supplement), p 5].
  • a second preferable physical form of the image-enhancing agents of the present invention is one of microspheres.
  • the preferable size range of these microspheres is between 0.1 ⁇ m and 250 ⁇ m.
  • An NMR image-enhancing agent may be formed into microspheres, either before or after the addition of a paramagnetic metal ion such as that of gadolinium.
  • the resultant microspheres when administered at diameters less than 3 ⁇ m to a mammal by intravenous injection have been found to be taken up by organs such as the liver, spleen and bone marrow.
  • organs such as the liver, spleen and bone marrow.
  • the normal tissue components of these organs for example, are rendered selectively preferentially able to yield improved images arising from induced magnetic resonance signals.
  • microspheres of sizes 0.1 to 3.0 ⁇ m are preferable for image enhancement of liver, spleen and bone marrow; and microspheres of sizes 3 to 250 ⁇ m are preferable for image enhancement of lung
  • Another significant aspect of the present invention may involve the further rapid coupling of chelate-polymer image-enhancing agents themselves to proteins such as hormones, polyclonal or monoclonal antibodies or to a substance which secondarily binds either native or derivatized antibodies, (e.g., protein A, biotin or avidin).
  • This coupling may involve, for example, sodium periodate oxidation of vicinal sugar hydroxyl groups such as those of a polysaccharide and reduction of Schiff-bases by sodium borohydride to related, stable, covalent bonds with protein amino groups.
  • the specific binding characteristics of antibodies, when combined with multiply chelatively bound metal ions may be used to produce specific localization of large numbers of paramagnetic or particle-emitting ions within internal targets of interest, thus amplifying greatly the signal-modulating effects of each specifically localized substance and also preserving or improving the antibody-binding specificity, affinity and avidity.
  • the image-enhancing agents of the present invention are also usable to enhance images being produced from the scanning of gamma and positron particle emissions and by ultrasound detectors.
  • most of the general principles of NMR image-enhancement--except agent dose--apply the major difference being that now the chelated metal ion is respectively, a radioisotope which emits gamma particles, or one of the relatively nonradioisotopes which alters the velocity of transmitted and reflected ultrasound waves.
  • Preferable radioisotopic metals include 51chromium, 68gallium, 111indium, 99m technetium and its oxides.
  • Useful ultrasound metals (ions) include those of atomic number 20 (calcium), 25 and 26 (manganese and iron, respectively), preferably 57-70 (the rare earth series), and optimally 64 (gadolinium).
  • a general object of the present invention comprises formulation and use of an image-enhancing agent, most particularly for images induced by magnetic resonance.
  • This image-enhancing agent comprises a chelating agent bound to a water-soluble biodegradable polymer.
  • the agent may be utilized in soluble form or as microspheres.
  • the image-enhancing agent when administered to an animal, is primarily distributed in circulating blood, kidney and especially at sizes of 20,000 to 500,000 MW, also has the capacity to exit the vascular compartment selectively in regions of tumors and inflammations and focus these tissue lesions.
  • the image-enhancing agent upon administration by injection into animals, is preferentially cleared by and redistributed to liver, spleen and bone marrow.
  • microspheres may be introduced into the gastrointestinal tract for image visualization thereof.
  • the preferred metal e.g., gadolinium
  • the preferred metal will form insoluble oxides which are not absorbed internally, and are therefore nontoxic.
  • the acute enhancement of blood flow images may be accomplished with the soluble polymeric image-enhancing agent and is even more efficiently performed with the microsphere form.
  • a significant advantage of image enhancement with polymeric and microsphere chelators, in connection with the marginally toxic metals, particularly paramagnetic ones such as gadolinium, is a further reduction of necessary metal dose and decrease in toxicity over that which can be achieved by simple (low molecular weight) chelating agents alone.
  • image-enhancing agents of the present invention in soluble or microsphere form, are readily reconstituted for animal and patient administration. This reconstitution involves a simple vortex-type mixing, as compared to sonification in detergents used for protein-based microspheres.
  • the image-enhancing agents of the present invention are easily usable in any detection or imaging system involving administration of divalent or trivalent metallic marker ions.
  • the image or spectral enhancing agents of the present invention allow shorter image acquisition times for satisfactory internal resolutions. Shorter image acquisition times are generally adequate to produce satisfactory internal images because of the greater signal enhancement and image contrast produced per unit of chelated marker and total agent.
  • the use of the present image-enhancing agents allows an increased number of serial images to be obtained in the enhanced mode after a single administration of agent.
  • NMR image-enhancing agents comprise paramagnetic metals such as gadolinium ion
  • each gadolinium ion exhibits an increased relaxivity for adjacent magnetic nuclei (e.g. protons) and hence gives greater T1 signal enhancement.
  • This increased relaxivity is related to an increased dipolar correlation time of Gd due to slower molecular rotation of polymeric Gd, the hydrophilic polymer (which becomes completely hydrated and allows rapid on-off binding (hence relaxation) of adjacent paramagnetic nuclei (protons)).
  • Spacer groups are not required between the metal chelates and the polymeric carrier in order to obtain optimal paramagnetic relaxation potencies, however, they could be introduced if deemed advantageous for other purposes.
  • the small microsphere size allows access of hydrated magnetic nuclei to virtually all of the chelated paramagnetic ions.
  • these agents are preferably formulated as a sterile, physiologically balanced, aqueous solution (or suspension), whose pH for purposes of intravenous administration is either a) approximately 6.0 to 7.5 for biodistribution and localization of the soluble polymer, microspheres, or preformulated microaggregates; or b) 8.5 or greater for biodistribution and localization of microaggregates which were formed after conjugation of the chelator to soluble polymer, by electrostatic aggregation.
  • these agents may be lyophilized and supplied in the dried form for reconstitution in physiologic solutions just prior to administration.
  • these agents may be formulated as a physiological solution (or suspension) which contains additional substances to increase the viscosity or osmolality.
  • the agents may be further formulated according to standard pharmaceutical methods, as uncoated or coated, micro- or macrotablets, in order to provide additional protection against the acidic pH of the stomach, and thereby avoid the release of chelated metal ions, which typically occurs at gastric pH's.
  • Other additives, such as flavorings and colorings may be also incorporated according to standard pharmaceutical procedures.
  • the concentration of total active agent will be between 0.1% and 30% (weight/volume), typically between 5% and 25%, and preferably 20%.
  • Doses of the soluble polymeric and microsphere agents will vary depending on the paramagnetic metal and the route of administration. The following doses are given for intravenous administration.
  • soluble Gd-DTPA-dextran 70 the dose will be between 0.01 and 0.075 millimoles of Gd per kilogram body weight, with optimal image enhancement occurring typically at or below 0.03 millimoles of Gd per kilogram.
  • microsphere Gd-DTPA-dextran 70 For liver, spleen and/or bone marrow enhancement with the preferred embodiment, microsphere Gd-DTPA-dextran 70, the dose will be between 0.008 and 0.05 millimoles of Gd per kilogram, with optimal image enhancement occurring typically at or below 0.01 millimoles per kilogram.
  • the optimal dose of soluble Gd-DTPA-dextran 70 and microsphere Gd-DTPA-dextran 70 will occur, respectively, at or below 0.08 and 0.04 millimoles Gd per kilogram.
  • Fe+3 as the dextran-iron oxide (in which the iron is complexed loosely to the hydroxyl groups of dextran), was obtained as “Proferdex” (20% iron, w/w) (Fisons Pharmaceuticals) and tested, both before and after extensive dialysis (to remove loosely bound iron), for NMR T1-enhancing activity in vitro (using an IBM PC20 Minispectrometer, 20 MHz). This result was compared with those of Fe+3 in the forms of ferric nitrate [Fe(NO3)3.9H20, obtained from Sigma Chemicals, St.
  • dextran-iron was extensively dialyzed and the NMR T1 activity ratios of the entire molecules were compared by the 50% concentration method (above). By this method, only approximately 17.7% of the pre-dialysis iron remained complexed to the dextran carrier. This both explains the in vivo toxicity and indicates why dextran-iron (and by inference, other dextran-metal) oxide complexes are unlikely to represent preferred embodiments of the present invention. From these data, it was apparent that the preferred embodiment(s) for intravenous use would be more likely to comprise dextran carriers with covalently conjugated chelating groups which had stability constants for metal chelation which were significantly higher than those of dextran-iron oxide complexation (see following examples). However, dextran-iron could be of significant use for gastrointestinal and other parenteral applications in which iron release from the carrier was less critical.
  • the cyclic dianhydride of DTPA prepared by the method of Eckelman et al. [J. Pharm. Sci. V 64, pp 704-706 (1975)], was obtained in a highly pure form from Calbiochem-Behring Corp. 6.0 g of the cyclic dianhydride was added stepwise to 1.72 g of Dextran T70 (average MW 70,000 daltons, Pharmacia Chemicals) in a reaction solvent comprising HEPES buffer 115 mg/100 ml distilled water, pH 7.0 to 8.0 (maximally). The reaction was carried out with vigorous stirring at ambient temperatures for a 1 hr period with readjustment to pH 7.0 to 8.0 using NaOH, after each segmental addition of DTPA dianhydride.
  • the dextran-DTPA product was separated from unconjugated DTPA by dialysis against 200 volumes of distilled water at pH 5.5. As assessed by molecular filtration, 97.8% of the dextran-DTPA product had a molecular weight of less than 100,000 daltons and only 1.6% had a molecular weight greater than 300,000 daltons.
  • the dilute solution of dialyzed dextran-DTPA was concentrated to between 5% and 20% (w/v) by one of three methods: a) forced, filtered-air evaporation at room temperature (preferred); b) retention over a nitrogen pressurized, 10,000 MW cutoff filter (Amicon Corporation); or c) lyophilization and reconstitution in physiologic solutions.
  • the binding capacity of polymer was determined in advance and the quantity of Gd adjusted to be exactly stoichiometric, leaving neither free Gd nor free polymeric DTPA.
  • This standard complexometric titration was also used to quantify total gadolinium of each preparation after oxidative acid hydrolysis of the organic matrix followed by neutralization of the released Gd.
  • one of every 12.2 sugar residues is conjugated to an active DTPA ligand, for a total of 32 Gd-binding ligands per 389 glucose units.
  • the concentrated product, Gd-DTPA-dextran was tested in an ionized calcium analyzer (Orion Biomedical Instruments) to assure that it had negligible calcium-binding capacity. This was done both as an additional check on the stoichiometry of Gd binding, and as a security measure to exclude any possibility of an acute decrease in serum calcium following intravenous injection (thereby avoiding cardiovascular complications and tetany).
  • microaggregates (ranging from 3 to 100 nanometers in diameter) are produced directly from the soluble Gd-DTPA-dextran T70 polymer by adding NaOH to the product (at a concentration of at least 8% (w/v) in 0.02 M phosphate buffer + 0.15 M NaCl) until the final pH is 8.2 or greater (preferably 8.5-9.0) and incubating the product for 16-48 hours at either room temperature or 4°C.
  • Microaggregates form based on ionic charge effects, and these are stable from the standpoint of biodistribution to reticuloendothelial organs following intravenous administration (see Example 3).
  • N,N-dimethylformamide (preferred due to favorable temperature stability).
  • a second solvent expected to allow comparable conjugation is N,N-diethylacetamide; this may have a biological advantage comprising improved susceptibility of its two-carbon fragments to metabolism, and hence, reduced toxicity in vivo if trace quantities of organic solvent remained with the DTPA-dextran following dialysis. Because neither of the substrates (dextran nor DTPA anhydride) are fully soluble in N,N-dimethylformamide the kinetics of conjugation are quite slow (ca. 12 to 16 hours).
  • NaOH was added either a) in the form of powdered pellets at the completion of conjugation, just prior to hydrolyzing any excess unreacted DTPA dianhydride with a 2-fold excess of water (with vigorous stirring and sonification); or b) in the form of an aqueous solution, at the same time as hydrolysis of any excess unreacted DTPA dianhydride (both methods gave equivalent results).
  • the quantity of NaOH was carefully adjusted to give a pH of 6.0 upon formation of the aqueous mixture.
  • aqueous- rather than organic-phase conjugations are the preferred methods for synthesizing polymeric intravascular contrast agents because organic-phase synthesis does not allow the formulation of completely soluble (noncross-linked) products. This feature is imperative for medical utility and regulatory acceptance.
  • Dextran-DTPA image-enhancing agents particularly with entrained gadolinium were produced under a variety of conditions and with different dextrans in various batches. Each batch was lyophilized and, when stored at room temperature, found to be stable at 22°C in excess of 1 year. Physiologic solutions of these agents were equally stable and gave no release of free Gd after 1 year at 4°C. Particular batches of dextran-DTPA image-enhancing agents were prepared having molecular weights of 10,000, 40,000 and 70,000 daltons although the method is usable for a size range of at least from 1,000 daltons to 2,000,000 daltons.
  • the increased rotational correlation time of the dextran macromolecule and its hydrophilic nature (which allows rapid on-off binding of water protons) amplify the paramagnetic efficiency (specific activity) of each Gd by multiples of 4.5 for the aqueous conjugate (soluble) and 2.2 for the nonaqueous conjugate (microaggregates) (see Example 4, Table).
  • the net negative charge of hydroxyl groups on the glucose residues (which are slightly ionized at physiologic pH) contributes to stabilization of Gd+3 binding by electrostatic effects and hence increases the Gd stability constant to significantly above 1017. The combination of these properties cause the dose, in vivo bioexchange and toxicity of Gd to be substantially decreased.
  • the high derivatization ratio (Gd-DTPA per dextran) also minimizes the amount of carrier material required for MR image enhancement in vivo . This reduces the total osmolality to levels which allow acute intravenous injection of MRI doses without producing unacceptable acute plasma volume expansion.
  • the soluble, 78,000 MW dextran-DTPA gadolinium chelates described in Example 1 have been injected directly into mice and rats.
  • the chelated Gd has a blood clearance whose two major components have t1/2's of about 50 and 180 minutes, as assessed by radioisotopic 153Gd. This provides up to a 3-fold increase in the MR imaging window compared to Gd-DTPA.
  • the flexibility exists for coupling DTPA to biocompatible carbohydrate carriers of various molecular weights, ranging from 1,000 to 2,000,000 daltons. By using shorter chain lengths than 70,000 daltons (e.g.
  • Alternative mono-, di-, oligo- and polysaccharides potentially include alpha, beta and gamma cyclodextrins, poly-cyclodextrins, glucose, glycogen, maltose, starch (and its derivatives, e.g., hydroxyethyl, carboxymethyl-, and aminoethyl-) blood-group oligosaccharides and their derivative amines, mucopolysaccharides and their oligomers, heparins, heparan, heparan-SO4, chondroitin-SO4, dermatan-SO4, and related, natural and synthetic, water-soluble polycarbohydrates and their derivatives.
  • mice the blood clearance of the Gd in 153Gd-DTPA-dextran 70 occurs in 1/2 to 1/3 the (t1/2) time observed in rats (above). Whereas clearance in rats is more predictive of that in humans, this accelerated clearance in mice has important implications for several of the subsequent examples involving in vivo potencies (in both the T1-relaxation and MR imaging modes), as follows. First, comparison of these NMR changes at a fixed time interval (e.g. 30 minutes post-injection) will make the soluble polymer appear to be more potent (for tumor imaging) in rats than in mice, whereas, if compared at times of equal blood levels, these two species of animal give equal results.
  • a fixed time interval e.g. 30 minutes post-injection
  • the microsphere formulation will appear to be considerably more potent (at enhancing liver) than is the soluble polymer (at enhancing tumors). This is because microsphere clearance from the liver occurs an order of magnitude more slowly (see below) than does soluble polymer clearance from a typical tumor.
  • the soluble polymer is actually very similar in potency to microspheres.
  • the t1/2 for blood clearance of the Gd in Gd-DTPA-dextran microspheres is ca. 15-20 minutes (as assessed by NMR T1 changes in the freshly excised organs).
  • ca. 50% of this microsphere Gd is cleared within ca. 2 hours by the kidneys (same method).
  • Initial studies (using both radioisotopic 153Gd and NMR T1 methods) indicate that the residual fraction of microsphere Gd which remains entrapped in the liver beyond 2 hours, clears with a t1/2 of 5-6 days. This slower clearance occurs by both the gastrointestinal (major) and renal (minor) routes and is comparable in rate to that for the liver clearance of native dextran 70.
  • the blood clearance of the Gd in Gd-DTPA-dextran microaggregates ranged from 60-240 minutes depending of their size (t1/2's increasing with smaller size -- 153Gd method). Biodistributions also varied depending on size, however, typically 40% to 75% of the agent was cleared by the liver. Maximal liver levels occurred at 24 hours post injection. Subsequent liver clearance occurred with a t1/2 of 5-6 days (same method).
  • tumor concentrations were reduced absolutely due to: a) strong competitive uptake by the liver, and b) the inaccessibility of supramolecular aggregates to tumors because of the smaller size of tumor capillary "pores".
  • the soluble polymer of Example 2 has also been reformulated as very small (0.1-0.5 ⁇ m) hydrophilic microspheres, by a modification of the method reported by the Applicant in a recent issue of Science [V 227, p 182 (1985)].
  • this method involved first the emulsification of the dextran-DTPA-Gd complex in an oil such as cottonseed oil. The emulsified complex was then sonicated to produce smaller microspheres. The oil was extracted with a volatile organic solvent (ether or hexanes) and the microspheres were lyophilized.
  • microsphere-Gd and polymer-Gd have almost identical T1 activities in vitro . This is consistent with the reported finding that increments in Gd relaxivity, which are produced by macromolecular coupling, plateau at macromolecular weights ⁇ 65,000 daltons [Lauffer et al. (1985) Mag. Res. Imaging V 3, p 11]. Hence, the slower rotation of microspheres relative to the soluble polymer, is not expected to give any further improvement in the relaxivity of microsphere-Gd over soluble macromolecular Gd (except potentially under flow conditions -- see Example 8, below.
  • the microspheres are cleared (captured initially) spontaneously by the liver, spleen and bone marrow of mice and rats (at a t1/2 of approximately 15 minutes). Here, they undergo controlled dissolution to the soluble polymer at a t1/2 of 30 minutes. This selectively enhances NMR images of the preceding organs.
  • Optimal T1 decreases have been obtained in the livers of mice using lower injected doses of Gd (0.01 to 0.02 mmoles/kg) than are normally used for standard contrast enhancement in clinical imaging (Gd-DTPA, 0.10 to 0.30 mmoles/kg). The latter agent produces minimal changes in liver T1's at the usual 30-minute imaging interval.
  • microsphere doses 10 to 27 times lower than those required for Gd-DTPA are produced with microsphere doses 10 to 27 times lower than those required for Gd-DTPA.
  • This significant dose advantage is produced by the combined effects of four design features: the increased rotational correlation time of microsphere-Gd, the improved permeation of water protons into the hydrophilic matrix and rapid on-off binding to (or near) Gd, the extremely small diameters of the microspheres, and the selective uptake of microspheres by target organs.
  • these microspheres are effective in vivo at the lowest doses of any formulation reported (down to 0.007 mmoles/kg).
  • Sprague-Dawley rats were imaged using a 0.35-Tesla, Diasonics clinical MR imaging system and a 30-cm rf coil.
  • Three clinically relevant pulse sequences were used: 1) spin-echo with a TR of 0.5 seconds (for T1-weighted images), 2) inversion-recovery (IR) (for T1-weighted images), and 3) spin-echo with a TR of 2.0 seconds (for T2-weighted images).
  • Diasonics software was used to calculate the area-averaged tissue intensities before and after injection of contrast agents.
  • Dual pulse sequences spin-echo, with TR's of 0.5 and 1.5 seconds or 1.0 and 2.0 seconds were also used to calculate the in vivo T1 relaxation times.
  • T1 and T2 relaxation times of freshly excised organs decreased in proportion to those obtained from the imager.
  • T1 changes uniformly exceeded the changes in T2 times.
  • the normalized in vitro T1 changes in rat spleens were: % Decrease in T1 of Spleen (35 min post vs. pre) 1.
  • Gd:DTPA dimeglumine 14.4 2.
  • Gd:DTPA-dextran microspheres gave markedly improved enhancement of MR images and/or T1 relaxation in the predicted target organs: liver, bone marrow and spleen.
  • the Gd:DTPA-dextran microspheres produced a selective enhancement of the tumor (by visual inspection) in relation to surrounding normal liver and all other organs of the rat. Tumor enhancement was maximal in the T1 modes (spin-echo with TR's of 0.5 and 1.0 sec; and inversion recovery) but was also observed in the T2 mode (spin-echo with TR of 2.0 sec). Tumor enhancement became strong at 25 minutes post-injection and persisted unchanged over the 2.5 hour interval of post-injection imaging. Gd:DTPA-dextran microspheres (at 0.011 mmoles/kg) produced image enhancement comparable in intensity to that of Gd:DTPA dimeglumine (at 0.1 mmoles/kg).
  • the percentage decrease in T2 relaxation of tumor tissue post-injection was approximately 2/3 of that observed for T1.
  • the result of enhancement was to brighten the tumor image in relation to surrounding normal liver and other abdominal organs.
  • Gd:DTPA-dextran microspheres as an enhancing agent for liver lesions (and also for spleen and bone marrow lesions) include:
  • mice bearing 1 cm transplantable, syngenic RIF sarcomas in their legs (see Examples above), were injected i.v. with two soluble polymeric forms of Gd:DTPA-dextran at a Gd dose of 0.09 mmoles/kg.
  • Tumors, livers and kidneys were excised from pre- and post-injection animals at 60-75 min after injection, and the T1 relaxation times of organs and tumor were determined in the IBM PC20 Minispectrometer for the effects of localized Gd.
  • Organ/Tissue MW of Polymer (/1000) T1 of Control (msec) % Decrease post-injection 1.
  • Tumor 70 804 15.7 10 " 3.2 2.
  • the soluble Gd:DTPA-dextran polymer injected at a comparable Gd dose, produced analogous but slightly weaker enhancements.
  • the superior performance of microspheres under flow conditions suggests that factors related to flow turbulence are more effectively overcome by particles that by molecular carriers, and by larger molecules than smaller ones.
  • This interpretation is supported by the finding that the very small MW enhancing agent, Gd-DTPA (dimeglumine) was almost completely ineffective. This ineffectiveness held true even when injections were made directly into the heart and imaged immediately with cardiac gating (R. Peshock, unpublished studies).
  • the two new contrast agents are the only ones potent enough to produce noninvasive enhancement of blood flow images with the available methods of clinical MR cardiac imaging.
  • the LD20 of Gd-DTPA-dextran microspheres was > 1,250 mg/kg. To put this in perspective, image enhancement is carried out at less than 1/5th to 1/11th of the LD20 dose, depending on the preparation used. Also, histologic assessment of the major organs excised after MR spectroscopy (in CBA mice) and MR imaging (in Sprague-Dawley and Buffalo rats) revealed no evidence of acute (30-60min) toxicity.
  • GdCl3.7.05H20 (327 mg) was adjusted to pH 5, added dropwise to the DTPA-glycerol resin and again sheared for 3 hours to maximally solubilize the material.
  • the residual larger gel-state material was separated by centrifugation at 250 x g for 15 min, and the smaller soluble fraction was saved and separated from residual free Gd by molecular filtration (with 4 washes of distilled water, pH 5.0) through a 1000 MW cutoff filter under pressurized nitrogen. The retentate was saved and centrifuged for an additional 15 min at 1000 x g and the supernatant of this was saved and lyophilized 16 hours.
  • the resulting glycerol-DTPA:Gd copolymer was minimally to negligibly cross-linked as determined by molecular filtration, which gave a size range (for 95% of the material) of 1,000 to 10,000MW, with an estimated average of 2,200 MW. This confirmed that the copolymeric units were soluble but that they had a tendency, as formulated presently, to undergo ionic intermolecular aggregation at a high concentration, which was reversible at a low concentration.
  • Gd:DTPA-glycerol copolymer was 1.9 times as active as Gd:DTPA dimeglumine. Its R1 was greater than 100/(mM and sec).
  • Gd:DTPA-glycerol copolymer was considerably more active as a MR enhancing agent for liver than was Gd:DTPA dimeglumine on both a weight and Gd molar basis.
  • this effect should be overcome by formulations which decrease intermolecular aggregation by altering electrostatic charge or pH; or by adding inert, chain-separating molecules.
  • Preliminary acute toxicologic studies were very slightly inferior to those of the Gd:DTPA-dextran soluble polymer. It is anticipated that this toxicity should be improved by substituting the hexadentate chelator, TTHA, for DTPA. This would leave 4 carboxylic acid groups available for Gd chelation (as with DTPA-dextran), and hence, theoretically decrease Gd bioexchange in vivo .
  • This method allows the direct covalent conjugation of antibodies and other receptor binding proteins or peptides via their reactive amino groups; and the indirect coupling of (a) biotinylated antibodies (commercially available) to avidin-derivatized polymer or spheres; or (b) native antibodies to polymer or spheres pre-derivatized with Protein A (Pharmacia Chemicals) which binds the Fc region of antibodies at high affinities.
  • This emulsion was added dropwise to a preheated (140°C) rapidly stirring, 100-ml volume of cottonseed oil, in order to heat denature (stabilize) the albumin matrix and maintain the integrity of particles and entrapment of Gd:DTPA upon subsequent suspension in injection medium. Heating at 140°C was continued for 10 min with high-speed shearing. The emulsion was cooled to 220°C with continued mixing. Oil was extracted with 6 x 60 ml of fresh diethyl ether (containing antioxidant) (Fisher Scientific Co.), and the resulting microspheres were lyophilized for 16 hrs to remove residual ether. Particles ranged from 0.1-0.5 ⁇ m (diameter) with a mean of 0.3 ⁇ m (monitored by light and electron microscopy).
  • Microspheres (Gd:DTPA:dimeglumine:albumin) were tested in vitro using a 20 MHz pulsed Nuclear Magnetic Resonance (NMR) spectrometer, for their capacity to reduce the T1 relaxation time of water protons in physiologic saline solution (0.02 M phosphate-buffered, 0.15 M NaCl). Activity was expressed as the concentration of material required to decease the T1 relaxation time to 50% of the value for phosphate-buffered saline (ID50). Microspheres were suspended at a concentration of 1 mg/ml by brief sonification.
  • NMR Nuclear Magnetic Resonance
  • albumin microspheres have a fast-release (surface) component of Gd:DTPA as well as a controlled-release (interior) component, the spheres were washed, resuspended, and diluted serially for testing.
  • Material ID50 total weight
  • Unwashed microsphere suspension 0.25 mg/ml
  • Fast-release supernatant 0.30 mg/ml
  • Washed microspheres 3.8 mg/ml
  • Microspheres (Gd:DTPA:dimeglumine:albumin) were tested in vivo by injecting them intravenously into 25 gm CBA mice (2 animals per group), allowing 30 minutes for uptake and sequestration by liver Kupffer cells, sacrificing the mice, and testing the excised organs.
  • the acute (30-min) biodistribution was determined by injecting microspheres trace-labeled with 125I-albumin. Radioisotope was quantified in a standard gamma counter.
  • liver and spleen are typical of that for small ( ⁇ 3 ⁇ m) particles.
  • the T1-weighted proton relaxation times of mouse livers were quantified by determining the whole-organ T1 relaxation time in a 20 MHz NMR spectrometer.
  • Injected material Liver T1 (msec) % of Control Saline (0.15 M) 332 Control Albumin microspheres (45 mg/kg, total wt; 0.1 mmol/kg Gd) 314 94.5 Gd:DTPA dimeglumine (0.1 mmol/kg Gd) 327 98.5
  • Solution 1 Diethylenetriamine pentaacetic acid, 0.72 gm (DTPA, Sigma Chemical Co.) was dissolved in 2.5 ml distilled water, the pH adjusted to 7.2 with NaOH, mixed with GdCl3.6H2O, 0.34 gm, and the solution readjusted to pH 7.2 and stirred for 20 min to allow complete chelation of Gd.
  • Solution 2. Diethylaminoethyl dextran (DEAE dextran, 500,000 MW with 1 positively charged group per 3 glucose residues, Sigma Chemical Co.) was dissolved by warming a saturated solution of 1 gm in 2.5 ml of distilled water.
  • DEAE dextran Diethylaminoethyl dextran, 500,000 MW with 1 positively charged group per 3 glucose residues, Sigma Chemical Co.
  • This emulsion was sonicated for 6 min. (with continuous magnetic stirring) using a 20,000 Hz ultrasonifier with a 3 mm special microtip (Heat Systems, Inc.) to disrupt the aqueous phase into 0.2-0.4 ⁇ m microdroplets.
  • Microparticles were stabilized and water removed by heating to 120°C for 20 min with vigorous stirring. After cooling, oil was removed with 3 x 60 ml of fresh diethyl ether (containing antioxidant) (Fisher Scientific Co.), and the sample lyophilized for 16 hrs.
  • Microspheres ranged from 0.1 to 0.3 ⁇ m, with a mean diameter of 0.2 ⁇ m. Unloaded DTPA:DEAE-dextran microspheres.
  • microsphere formulation was prepared without chelated Gd (or other metal ions), by dissolving DTPA, adjusting the pH to 7.2, and mixing this with a 1 gm solution of DEAE dextran, all prepared as described above.
  • the aqueous phase was emulsified in cottonseed oil and processed as described above.
  • Test materials were diluted serially and assayed for proton T1 relaxivities using a 20 MHz pulsed NMR spectrometer as described in Example 3. These materials contained very minor components of fast-released Gd and Gd:DTPA chelate (less than 2% of the totals). Thus, it was not necessary to wash and resuspend the materials prior to NMR testing.
  • the soluble Gd:DTPA:DEAE-dextran polymer was 1.96 times more potent than Gd:DTPA dimeglumine. This improved relaxivity was attributable to strong nonvocalent binding of the negatively charged, DTPA moiety of Gd:DTPA to the positively charged, DEAE substituent groups of dextran polymer.
  • the large size of this polymer (300,00 MW) resulted in a longer rotational correlation time for each noncovalently bound Gd:DTPA and allowed improved transfer of energy from water protons to paramagnetic Gd ions.
  • Fe:DTPA:DEAE-dextran microspheres were suspended at 1 mg/ml in a 70% ethanol-water solution, 10-50 ⁇ l aliquots were placed on cytologic glass slides, the microspheres were sedimented at 750 x g for 12 min. in a cytocentrifuge, slides were air dried, and microsphere:Fe+3 was stained for histologic analysis by the Prussian blue, acidic ferro-ferricyanide procedure. Dark blue reaction product formed over each microsphere, as assessed by standard light microscopy. Hence, the chelated Fe+3, which was initially bound to microsphere DTPA at neutral pH, became dissociated sufficiently by the acidic pH of the staining solution to allow histochemical detection in vitro .
  • Test materials were injected i.v. into 25 gm CBA mice. At 30 min the mice were sacrificed by decapitation (exsanguination) and the excised livers and kidneys assessed for changes in proton T1 relaxation times (20 MHz; IR pulse sequence). Doses of test materials were made equivalent based on in vitro potency (ID50 analysis). Material Dose (mmol/kg) T1 (% of control)* Liver Kidney Gd:DTPA:DEAE dextran soluble polymer 0.23 69 28 Gd:DTPA:DEAE dextran microspheres 0.23 81 78 Gd:DTPA dimeglumine 0.47 83 24 *The T1's of control organs were 330 msec for liver and 385 msec for kidney.
  • the soluble polymeric formulation of Gd:DTPA:DEAE dextran was the most potent substance for liver (approximately 4 times as potent as Gd:DTPA dimeglumine, which produced a significantly greater decrease in kidney).
  • the microsphere form of Gd:DTPA:DEAE dextran was approximately 2 times as potent in liver as Gd:DTPA dimeglumine. Because of selective organ uptake by the liver, it produced a much smaller effect in kidney. Gd:DTPA dimeglumine was relatively ineffective at decreasing the T1 of liver even at very high doses which produced marked decreases in kidney. (The usual dose of the dimeglumine formulation used for Phase III clinical trials is 0.1 mmol/kg.)
  • T1-weighted images using both a spin-echo pulse sequence at TR's of 0.5, 1.5 and 2.0, and an
  • test materials were as follows: Gd (mmol/kg) Gd:DTPA:DEAE dextran soluble polymer 0.30 Gd:DTPA:DEAE dextran microspheres 0.15 Gd:DTPA dimeglumine 0.30
  • Fe+3:DTPA:DEAE-dextran microspheres (prepared as in Example 14) were injected into a CBA mouse at a dose of 140 mg/kg. Thirty minutes after injection, the animal was sacrificed, and the liver and spleen were excised. The tissues were fixed in formalin and stained using the Prussion blue (acidic ferro-ferricyanide) iron staining technique, to identify cellular locations of microsphere iron. By microscopic evaluation, 0.1-0.6 ⁇ m (diameter) heavy concentrations (3+/4+) of iron-positive particles were present in Kupffer cells of the liver and sinusoidal macrophages of the spleen.
  • Prussion blue acidic ferro-ferricyanide
  • the rats of Example 17 which were injected with soluble polymeric and microsphere Gd noncovalently bound (paired-ion) paired to DEAE dextran, developed mild-to-moderate respiratory distress between 90 and 120 minutes after the injection of test materials. Based on these observations, histologic evaluation was performed on the formalin-fixed organs (brain, heart, lungs, liver, spleen and kidneys) from these rats and from CBA-strain mice injected with the same material at identical doses. The lungs, liver and kidneys of both the rats and mice revealed slight-to-moderate acute congestion of the small blood vessels with red blood cells. Additionally, the kidneys showed moderate acute cortical edema (accumulation of protein-poor fluid).
  • Examples 16 and 18 establish the efficacy (but not the biological compatibility) of Gd:DTPA noncovalently bound to polycationic carriers, as prototype formulations for preferential MR image enhancement of liver, spleen and bone marrow.
  • the microsphere formulation was approximately twice as active as the soluble one.
  • Microspheres were injected intravenously into CBA mice at a dose calculated to deliver 0.19 mmol of Gd/kg.
  • the percentage decreases in proton T1 relaxations of the experimental versus control (uninjected) organs excised at 30 minutes were: Liver 6% Kidney 53%
  • microspheres were not sufficiently stabilized to remain intact long enough for clearance by the liver and spleen (requiring approximately 15 minutes).
  • supplementary matrix materials such as 70,000 MW dextran, would be expected to confer this required stability.
  • the preferred embodiments were covalently conjugated dextran-DTPA polymers and microspheres in conjunction with chelated Gd.
  • FeCl3.6H2O was added in a stoichiometric quantity to DTPA-Dextran T10 (11,000 MW soluble polymer) and the T1 ID50's compared with those of comparably loaded Fe:DTPA and Fe:desferrioxamine (a low molecular weight iron chelator of bacterial origin.
  • MR imaging is performed on a Diasonics 0.35T instrument, using a 30-cm rf coil, and a T1-weighted spin-echo pulse sequence (TR 500, TE 40).
  • Pentobarbital is used for animal anesthesia in order to avoid drug modulation of image intensities.
  • T1 relaxation were performed on the freshly excised organs. In general, these T1's decreased in proportion to increased image intensities. Deviations from this relationship were observed for enhancement with Gd:DTPA dimeglumine if the interval between peak image contrast and sacrifice of the animals became unusually prolonged.
  • Gd-DTPA-dextran T70 and Gd-DTPA were compared by injecting both agents at the limiting dose for Gd:DTPA dimeglumine of 0.03 mmol Gd per kg. Under these limiting conditions, enhancement of the BRO melanoma occurred prominently with Gd:DTPA-dextran T70 but was barely perceptible with Gd:DTPA dimeglumine which required a dose 1/2 log higher. Image contrast was maintained for a significantly longer post-injection interval by Gd:DTPA*dextran T70 than Gd:DTPA dimeglumine.
  • the new soluble polymeric agent had the following advantages:
  • chemical advantages such as increased stability of metal ion chelation or increased flexibility of the carrier polymer, may be achieved by using conjugation reactions other than direct derivatization with dicyclic DTPA anhydride.
  • the middle acetate group of DTPA may be selectively reacted with ethylene diamine before decylizing the stronger-chelating carboxylic anhydrides This may be accomplished by conjugation in dried organic solvents such as N,N-dimethylformamide or N,N-diethylacetamide using standard organic-soluble carbodiimide techniques.
  • the amine-derivatized DTPA could then be reacted in aqueous solvents, using water-soluble carbodiimide reagents, with the OH-groups of native dextran, the aldehyde groups of sodium periodate-oxidized dextran (more reactive), or the carboxylic acid groups of succinylated dextran (most reactive) which had been prepared by prior reaction with succinic anhydride.
  • the simple DTPA chelate could be stabilized in its most favored chelation state by prebinding Gd, followed by conjugation to ethylenediamine in aqueous solvents using water-soluble carbodiimide.
  • Such metal-protection techniques are common methods for protecting enzyme active sites during enzyme chemical reactions/purifications.
  • the resulting dextran conjugate might have even higher binding stability for Gd and other paramagnetic metals than does the completely acceptable conjugate described as the preferred embodiment in the present application.
  • Additional alternative methods for potentially improved or diversified conjugation include: (1) modified acid-catalyzed di-anhydride-alcohol reactions [W.C. Eckelman, et al., J. Pharm. Sci. (1975), 643:704]; (2) amide coupling linkages between ethylenediamine-derivatized DTPA and succinylated dextran as modified from [D.J. Hnatowich et al., J. Nuc. Med.
  • radionuclide quantification of Gd binding to the DTPA-dextran soluble polymer was performed using 153Gd, in collaboration with Padmaker Kulkarni, Ph.D. [Radiology, Imaging Center, University of Texas Health Science Center, Dallas, (UTHSCD)]; and magnetic resonance imaging was performed on the University's Diasonics 0.35T clinical magnet in a 30cm rf head coil using T1-weighted, spin-echo and inversion-recovery pulse sequences, in collaboration with Jeffrey Weinreb, M.D., William Erdman, M.D., and Jesse Cohen, M.D., Nuclear Magnetic Resonance Imaging Center-Radiology, University of Texas Health Sciences Center, Dallas, Texas.

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Claims (46)

  1. Verfahren zur Herstellung eines bildverstärkenden Mittels oder eines spektral verstärkenden Mittels, wobei ein biologisch abbaubares, wasserlösliches Polymer, das sich wiederholende hydrophile monomere Einheiten mit Amino- und/oder Hydroxylgruppen enthält, mit einem Cheliermittel kovalent gekuppelt wird, wobei sich die funktionellen Gruppen des Cheliermittels mit den reaktiven Gruppen der monomeren Einheiten des Polymers verbinden und das Cheliermittel mit einem Metallion assoziiert ist, dadurch gekennzeichnet, daß die Kupplung des wasserlöslichen Polymers und des Cheliermittels in einem wäßrigen, protonenhaltigen Lösungsmittel durchgeführt wird und daß das Cheliermittel bei physiologischen Temperaturen und pH-Werten eine Bildungskonstante für zweiwertige oder dreiwertige Metallkationen von mindestens 10⁸ hat.
  2. Verfahren nach Anspruch 1, worin das bildverstärkende Mittel oder das spektral verstärkende Mittel ein Molekulargewicht im Bereich von 1000 - 2.000.000 Dalton hat.
  3. Verfahren nach Anspruch 1 oder 2, worin das bildverstärkende Mittel oder das spektral verstärkende Mittel weniger als 5 % (Gew./Gew.) vernetzte oder mikroaggregierte Bestandteile enthält und biologisch abbaubar ist.
  4. Verfahren nach einem der vorhergehenden Ansprüche, worin das Cheliermittel bei physiologischen Temperaturen und pH-Werten eine Bildungskonstante für zweiwertige oder dreiwertige Metallionen von mindestens 10⁸ hat.
  5. Verfahren nach einem der vorhergehenden Ansprüche, worin das Cheliermittel bei physiologischen Temperaturen und pH-Werten eine Bildungskonstante für zweiwertige oder dreiwertige Metallkationen von mindestens 10¹⁷ hat.
  6. Verfahren nach einem der Ansprüche 1 bis 5, worin die Kupplung unter solchen Bedingungen durchgeführt wird, daß
       das Polymer ausreichend verdünnt ist, um eine kovalente intermolekulare Vernetzung zu vermeiden, wenn eine Vorstufe des Cheliermittels graduell, kontinuierlich oder stufenweise unter kräftigem Mischen zugesetzt wird, und der pH-Wert der Lösung so eingestellt wird, daß ein zunächst gebildetes lösliches Polymer-Cheliermittel-Konjugat sowohl vor als auch nach der Chelierung der Metallionen in einem vollständig wasserlöslichen Zustand gehalten wird.
  7. Verfahren nach einem der Ansprüche 1 bis 6, worin das Metallion ein paramagnetisches Metallion ist.
  8. Verfahren nach Anspruch 7, worin das paramagnetische Metallion ein Ion des Gadoliniums, Eisens, Nickels, Kupfers, Erbiums, Europiums, Dysprosiums, Holmiums, Chroms oder Mangans, vorzugsweise des Gadoliniums, ist.
  9. Verfahren nach einem der Ansprüche 1 bis 8, worin das Metallion ein nicht-radioisotopes Metallion ist.
  10. Verfahren nach einem der Ansprüche 1 bis 8, worin das Metallion ein radioisotopes Metallion ist, das Gammastrahlen emittiert.
  11. Verfahren nach einem der Ansprüche 1 bis 10, worin das Cheliermittel Triethylentetraminhexaessigsäure (TTHA), Diethylentriaminpentaessigsäure (DTPA), Ethylendiamintetraessigsäure (EDTA) oder 1,4,7,10-Tetraazacyclodecan-N,N',N'',N'''-tetraessigsäure (DOTA), oder ein synthetisches Derivat von TTHA, DTPA, EDTA oder DOTA ist.
  12. Verfahren nach Anspruch 11, worin das Cheliermittel DTPA ist.
  13. Verfahren nach einem der Ansprüche 1 bis 12, worin das wasserlösliche Polymer ein Mono-, Di-, Poly- oder Oligosaccharid und deren Aminderivate, Mucopolysaccharide und deren Oligomere, Heparin, Heparan, Heparan-SO₄, Chondroitin-SO₄, Dermatan-SO₄ und verwandte natürliche und synthetische wasserlösliche Polykohlenhydrate und deren Derivate umfaßt.
  14. Verfahren nach Anspruch 13, worin das wasserlösliche Polymer Heparin, Heparansulfat, Chondroitinsulfat, Dermatansulfat, Stärke, Carboxymethylstärke oder Hydroxyethylstärke, einzeln, in Kombination miteinander oder mit DEAE-Dextran umfaßt.
  15. Verfahren nach Anspruch 14, worin das wasserlösliche Polymer Heparin und das Cheliermittel DTPA in Anwesenheit des N-Methylglucamin-Gegenions darstellt.
  16. Verfahren nach einem der Ansprüche 1 bis 15, worin das Polymer ein Molekulargewicht zwischen 1000 Dalton und 2.000.000 Dalton, vorzugsweise zwischen 40.000 Dalton und 75.000 Dalton, hat.
  17. Verfahren nach Anspruch 16, worin die funktionellen Gruppen Carboxylgruppen darstellen, die über eine Esterbindung an das Polymer gebunden sind, wobei das Cheliermittel vorzugsweise DTPA oder DOTA ist.
  18. Verfahren nach einem der Ansprüche 1 bis 17, worin das bildverstärkende Mittel das Produkt eines Cheliermittels, welches mindestens zwei Carboxylgruppen im Überschuß über die zur wirksamen Chelierung von zweiwertigem oder dreiwertigem Metall-Kationen erforderlichen besitzt, und eines Polyalkohols oder Kohlenhydrats darstellt.
  19. Verfahren nach Anspruch 18, worin das Cheliermittel DTPA und/oder der Polyalkohol oder das Kohlenhydrat Glycerin darstellt.
  20. Verfahren nach einem der Ansprüche 1 bis 19, worin das bildverstärkende Mittel Dextran, DTPA, das an das Dextran in einem DTPA/Monosaccharideinheit-Molverhältnis zwischen 1/5 und 1/25, sowie Gadolinium, das an das DTPA gebunden ist, enthält, wobei das Dextran ein Molekulargewicht zwischen 1000 Dalton und 2.000.000 Dalton hat.
  21. Verfahren nach Anspruch 20, worin das Dextran ein Molekulargewicht zwischen 40.000 Dalton und 75.000 Dalton hat.
  22. Verfahren nach Anspruch 20 oder 21, worin das Mittel eine mindestens 5 gew.-%ige DTPA darstellt.
  23. Verfahren nach einem der Ansprüche 1 bis 22, worin das Cheliermittel DTPA und das Polymer Dextran darstellt und worin bei der Konjugation des DTPA an das Dextran jeweils unter kräftigem Vermischen, das Dextran in destilliertem Wasser in einer Menge von 1,7 bis 2,0 g je 100 ml gelöst wird und 6 bis 8 g biscyclisches DTPA-Anhydrid stufenweise in Aliquots von etwa 0,3 g zugesetzt werden, während der pH-Wert der Reaktion zwischen 6,0 und 8,0 und der End-pH-Wert bei oder unterhalb 8,0 gehalten wird, und zwar sowohl vor als auch nach der Chelierung des Metallions in stöchiometrischen Mengen.
  24. Verfahren nach einem der Ansprüche 1 bis 23, worin das bildvestärkende Mittel anschließend an einen Antikörper oder an eine Substanz, die sekundär native oder derivatisierte Antikörper bindet, gebunden wird.
  25. Verfahren nach einem der Ansprüche 1 bis 24, worin das Mittel in einer im wesentlichen vollständig wasserlöslichen Form erzeugt wird und zur bildlichen Darstellung von:
       inneren Tumoren mit einer Potenz, die bei intravenöser Verabreichung mindestens das 3,3-fache von Gd-DTPA beträgt; und
       Körperhohlräumen sowie dem gastrointestinalen Trakt bei direkter Einführung
    brauchbar ist.
  26. Verfahren zur Herstellung eines bildverstärkenden Mittels, welches die physikalische Form von stabilisierten hydrophilen Mikrokugeln hat, die einen Durchmesser von 0,1µm bis 250µm, vorzugsweise von 0,1µm bis 0,5µm haben, wobei das Verfahren die Emulgierung des zunächst wasserlöslichen bildverstärkenden Mittels, welches nach einem Verfahren nach einem der Ansprüche 1 bis 23 erzeugt worden ist, in einer Ölphase umfaßt.
  27. Verfahren nach Anspruch 26, worin die gewünschten Mikrokugeldurchmesser von 0,1µm bis 250µm durch Ultraschallbehandlung, Hochgeschwindigkeitsscherung oder eine vergleichbare alternative Ultrahomogenisierungsmethode erhalten werden und/oder die gewünschten Auflösungsgeschwindigkeiten der Mikrokugeln in wäßrigen Lösungsmitteln durch Hitzestabilisierung, chemische Vernetzung, Ionenbindung (gepaarte Ionen) oder Kombinationen dieser physikalischen und chemischen Verfahren erzielt werden; worin das Öl extrahiert und das Präparat unter Verwendung von Ether, Hexan oder vergleichbaren flüchtigen organischen Lösungsmitteln sterilisiert wird; und worin die erhaltenen Mikrokugeln zur Trockenlagerung lyophilisiert werden.
  28. Verfahren nach Anspruch 26 oder 27, worin die polymere Matrix Dextran oder Heparin enthält, worin die Stabilisierung der Mikrokugeln gegen Auflösung in Wasser durch Erhitzen einer Ölphasen-Emulsion der Mikrokugeln bei 115°C bis 135°C über einen Zeitraum von 20 bis 40 Minuten vor der Extraktion des Öls mit einem organischen Lösungsmittel erreicht wird, worin das physikalisch eingeschlossene Cheliermittel DTPA ist und worin das paramagnetische Metallion Gadolinium ist.
  29. Verfahren nach Anspruch 28, worin die polymere Matrix Dextran ist und die Mikrokugeln einen gewünschten Mikrokugeldurchmesser zwischen 0,1µm und 250µm haben, der durch Ultraschallbehandlung unter kräftigem Rühren erzielt wird, wobei das Öl extrahiert und das Präparat unter Verwendung von Hexan sterilisiert wird.
  30. Verfahren nach Anspruch 27, worin die polymere Matrix Heparin und das Cheliermittel DTPA ist und die Auflösungsgeschwindigkeiten der Mikrokugeln in wäßrigen Lösungsmitteln durch Ionenbindung (gepaarte Ionen) von positiv geladenen quaternären Ammoniumionen erreicht werden.
  31. Verfahren nach einem der Ansprüche 26 bis 30, worin das Metallion nicht-radioaktiv ist und aus der Gruppe der Elemente mit Atomzahlen von 21 bis 29 und 57 bis 70 ausgewählt ist.
  32. Verfahren nach einem der Ansprüche 25 bis 31, worin das erzeugte Mittel in der physikalischen Form von stabilisierten hydrophilen Mikrokugeln vorliegt, die einen Durchmesser von 0,1µm bis 0,5µm haben und wobei das Mittel zur bildlichen Darstellung von
    a) Leber, Milz und Knochenmark mit einer Potenz, die bei intravenöser Verabreichung mindestens das 7-fache von Gd-DTPA beträgt; und
    b) allen Körperhohlräumen sowie dem gastrointestinalen Trakt bei direkter Einführung
    brauchbar ist.
  33. Verwendung eines Mittels, das nach einem Verfahren nach einem der Ansprüche 1 bis 32 hergestellt worden ist, bei der Herstellung einer Rezeptur zur Verstärkung der NMR-Bilder eines Patienten.
  34. Verwendung eines Mittels, das nach einem Verfahren nach einem der Ansprüche 1 bis 32 hergestellt worden ist, bei der Herstellung einer Zubereitung zur bildlichen Ultraschall-Darstellung.
  35. Bildverstärkendes Mittel oder spektral verstärkendes Mittel, hergestellt durch kovalente Kupplung in einem wäßrigen protonenhaltigen Lösungsmittel:
       eines biologisch abbaubaren, wasserlöslichen Polymers, das sich wiederholende hydrophile monomere Einheiten mit Amino-und/oder Hydroxylgruppen enthält;
       eines Cheliermittels, das bei physiologischen Temperaturen und pH-Werten eine Bildungskonstante für zweiwertige oder dreiwertige Metall-Kationen von mindestens 10⁸ hat, wobei sich die funktionellen Gruppen des Cheliermittels mit den reaktiven Gruppen der monomeren Einheiten des Polymers verbinden;
       und eines Metallions, das mit dem Cheliermittel assoziiert ist,
    wobei das bildverstärkende Mittel ein Molekulargewicht im Bereich von 1000 bis 2.000.000 Dalton hat und weniger als 5 % (Gew./Gew.) vernetzte oder mikroaggregierte Bestandteile enthält und biologisch abbaubar ist.
  36. Bildverstärkendes Mittel oder spektral verstärkendes Mittel nach Anspruch 35, worin das bei seiner Bildung verwendete Cheliermittel bei physiologischen Temperaturen und pH-Werten eine Bildungskonstante für zweiwertige oder dreiwertige Metallkationen von mindestens etwa 10¹³ hat.
  37. Bildverstärkendes Mittel oder spektral verstärkendes Mittel nach Anspruch 35, worin das bei seiner Bildung verwendete Cheliermittel bei physiologischen Temperaturen und pH-Werten eine Bildungskonstante für zweiwertige oder dreiwertige Metallkationen von mindestens etwa 10¹⁷ hat.
  38. Bildverstärkendes Mittel oder spektral verstärkendes Mittel nach einem der Ansprüche 35 bis 37, welches durch das spezifische Merkmal nach einem oder mehreren der Ansprüche 7 bis 23 modifiziert ist.
  39. Bildverstärkendes Mittel oder spektral verstärkendes Mittel nach einem der Ansprüche 35 bis 38, worin das wasserlösliche Polymer Dextran enthält und das Cheliermittel DTPA und das Metallion Gadolinium sind.
  40. Bildverstärkendes Mittel oder spektral verstärkendes Mittel nach einem der Ansprüche 35 bis 38, worin das Metallion Eisen ist.
  41. Bildverstärkendes Mittel oder spektral verstärkendes Mittel nach Anspruch 40, worin das Polymer Dextran enthält und das Cheliermittel DTPA ist.
  42. Bildverstärkendes Mittel oder spektral verstärkendes Mittel in der physikalischen Form von stabilisierten hydrophilen Mikrokugeln, die einen Durchmesser von 0,1µm bis 250µm haben und wobei das Mittel nach einem Verfahren hergestellt ist, welches die Stufe der Ölphasen-Emulgierung eines zunächst wasserlöslichen bildverstärkenden Mittels, das nach dem Verfahren nach einem der Ansprüche 1 bis 23 hergestellt worden ist, umfaßt.
  43. Mittel nach Anspruch 42, worin die gewünschten Mikrokugeldurchmesser von 0,1µm bis 250µm durch Ultraschallbehandlung, Hochgeschwindigkeitsscherung oder ein vergleichbares alternatives Ultrahomogenisierungsverfahren erhalten worden sind und worin die gewünschten Auflösungsgeschwindigkeit der Mikrokugeln in wäßrigen Lösungsmitteln durch Hitzestabilisierung, chemische Vernetzung, Ionenbindung (gepaarte Ionen) oder Kombinationen dieser physikalischen und chemischen Verfahren erzielt worden sind.
  44. Mittel nach Anspruch 43, worin das Öl extrahiert und das Präparat unter Verwendung von Ethern, Hexanen oder vergleichbaren flüchtigen organischen Lösungsmitteln stabilisiert worden ist, und worin die Mikrokugeln gegenbenenfalls für die Trockenlagerung lyophilisiert worden sind.
  45. Verfahren zur Herstellung eines bildverstärkenden Mittels oder eine spektral verstärkenden Mittels in der physikalischen Form von hydrophilen Mikroaggregaten, welches die Ionenbindung (gepaarte Ionen) eines zunächst wasserlöslichen bildverstärkenden Mittels, das nach dem Verfahren nach einem der Ansprüche 1 bis 23 hergestellt worden ist, umfaßt.
  46. Bildverstärkendes Mittel oder spektral verstärkendes Mittel in der physikalischen Form von hydrophilen Mikroaggregaten, welches durch Ionenbindung (gepaarte Ionen) eines zunächst wasserlöslichen bildverstärkenden Mittels nach einem der Ansprüche 35 bis 41 hergestellt worden ist.
EP86907195A 1985-11-18 1986-11-18 Polychelierende stoffe für abbildung- und spektralerhöhung (und spektrale verschiebung) Revoked EP0247156B1 (de)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008003682A1 (en) * 2006-07-06 2008-01-10 Novartis Ag Non invasive method for assessing mucus clearance

Families Citing this family (144)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU605461B2 (en) * 1986-04-07 1991-01-17 Francois Dietlin New compositions usable in tomo-densitometry
US4863713A (en) * 1986-06-23 1989-09-05 The Board Of Trustees Of Leland Stanford Jr. Univ. Method and system for administering therapeutic and diagnostic agents
US5055288A (en) * 1987-06-26 1991-10-08 Advanced Magnetics, Inc. Vascular magnetic imaging method and agent comprising biodegradeable superparamagnetic metal oxides
US5672334A (en) * 1991-01-16 1997-09-30 Access Pharmaceuticals, Inc. Invivo agents comprising cationic metal chelators with acidic saccharides and glycosaminoglycans
US5707604A (en) * 1986-11-18 1998-01-13 Access Pharmaceuticals, Inc. Vivo agents comprising metal-ion chelates with acidic saccharides and glycosaminoglycans, giving improved site-selective localization, uptake mechanism, sensitivity and kinetic-spatial profiles
DE3710730A1 (de) * 1987-03-31 1988-10-20 Schering Ag Substituierte komplexbildner, komplexe und komplexsalze, verfahren zu deren herstellung und diese enthaltende pharmazeutische mittel
MX12394A (es) * 1987-07-23 1993-12-01 Ciba Geigy Ag Procedimiento par la obtencion de carbamatos de polietilenglicol.
AU623901B2 (en) * 1988-01-26 1992-05-28 Nycomed As Paramagnetic compounds comprising chelating moiety, linker group macro molecule and paramagnetic metal
GB8801646D0 (en) * 1988-01-26 1988-02-24 Nycomed As Chemical compounds
US5681543A (en) * 1988-02-29 1997-10-28 Shering Aktiengesellschaft Polymer-bonded complexing agents and pharmaceutical agents containing them for MRI
US5260050A (en) * 1988-09-29 1993-11-09 Ranney David F Methods and compositions for magnetic resonance imaging comprising superparamagnetic ferromagnetically coupled chromium complexes
WO1990003190A1 (en) * 1988-09-29 1990-04-05 Ranney David F Methods and compositions for magnetic resonance imaging
US6274713B1 (en) * 1989-04-07 2001-08-14 Salutar, Inc. Polychelants
US5914095A (en) * 1989-04-07 1999-06-22 Salutar, Inc. Polychelants containg amide bonds
FR2654344B1 (fr) * 1989-11-16 1994-09-23 Cis Bio Int Complexe paramagnetique de gadolinium, son procede de preparation et son utilisation pour le diagnostic par irm.
IT1245748B (it) * 1990-12-21 1994-10-14 Mini Ricerca Scient Tecnolog Preparazione includente anticorpi monoclonali biotinilati, avidina e biotina, per la diagnosi di affezioni tumorali e suo impiego
DE4117782C2 (de) * 1991-05-28 1997-07-17 Diagnostikforschung Inst Nanokristalline magnetische Eisenoxid-Partikel, Verfahren zu ihrer Herstellung sowie diagnostische und/oder therapeutische Mittel
JP2901787B2 (ja) * 1991-07-15 1999-06-07 日本メジフィジックス株式会社 核磁気共鳴造影剤
US5409688A (en) * 1991-09-17 1995-04-25 Sonus Pharmaceuticals, Inc. Gaseous ultrasound contrast media
CZ286149B6 (cs) * 1991-09-17 2000-01-12 Sonus Pharmaceuticals, Inc. Plynná prostředí pro zvýšení kontrastnosti obrazu, získaného ultrazvukem a způsob výběru plynů pro toto použití
MX9205298A (es) 1991-09-17 1993-05-01 Steven Carl Quay Medios gaseosos de contraste de ultrasonido y metodo para seleccionar gases para usarse como medios de contraste de ultrasonido
US6723303B1 (en) 1991-09-17 2004-04-20 Amersham Health, As Ultrasound contrast agents including protein stabilized microspheres of perfluoropropane, perfluorobutane or perfluoropentane
JP2894879B2 (ja) * 1991-10-04 1999-05-24 日本メジフィジックス株式会社 診断用造影剤
GB9200065D0 (en) * 1992-01-03 1992-02-26 Nycomed As Contrast media
US5474765A (en) * 1992-03-23 1995-12-12 Ut Sw Medical Ctr At Dallas Preparation and use of steroid-polyanionic polymer-based conjugates targeted to vascular endothelial cells
DE69324591T3 (de) * 1992-08-05 2004-02-12 Meito Sangyo K.K., Nagoya Verbundmaterial mit kleinem durchmesser, welches ein wasserlösliches carboxylpolysaccharid und magnetisches eisenoxid enthaltet
US5330743A (en) * 1992-11-12 1994-07-19 Magnetic Research, Inc. Aminosaccharide contrast agents for magnetic resonance images
US5466439A (en) * 1992-11-12 1995-11-14 Magnetic Research, Inc. Polymeric contrast enhancing agents for magnetic resonance images
US5558855A (en) * 1993-01-25 1996-09-24 Sonus Pharmaceuticals Phase shift colloids as ultrasound contrast agents
NZ262237A (en) * 1993-01-25 1997-06-24 Sonus Pharma Inc Ultrasound contrast agents comprising phase shift colloids having a boiling point below the body temperature of the animal it is used in
IL108416A (en) 1993-01-25 1998-10-30 Sonus Pharma Inc Colloids with phase difference as contrast ultrasound agents
EP0683676A4 (de) * 1993-02-02 1998-09-30 Neorx Corp Gelenkte bioverteilung von kleinen molekülen.
US6203775B1 (en) * 1993-03-19 2001-03-20 The General Hospital Corporation Chelating polymers for labeling of proteins
US5482698A (en) * 1993-04-22 1996-01-09 Immunomedics, Inc. Detection and therapy of lesions with biotin/avidin polymer conjugates
PT711179E (pt) * 1993-07-30 2005-03-31 Imcor Pharmaceutical Company Composicoes de microbolhas estabilizadas para ultra-som
US5798091A (en) * 1993-07-30 1998-08-25 Alliance Pharmaceutical Corp. Stabilized gas emulsion containing phospholipid for ultrasound contrast enhancement
ITMI940055A1 (it) * 1994-01-18 1995-07-18 Bracco Spa Contenitore per soluzioni contrastografiche diagnostiche
US5540909A (en) * 1994-09-28 1996-07-30 Alliance Pharmaceutical Corp. Harmonic ultrasound imaging with microbubbles
JPH10509424A (ja) * 1994-10-03 1998-09-14 ザ トラスティーズ オブ ザ ユニバーシティー オブ ペンシルバニア 磁気共鳴イメージングで顕著な効果を示すキレート錯体
US6232295B1 (en) 1994-10-12 2001-05-15 Jon Faiz Kayyem Cell-specific contrast agent and gene delivery vehicles
US6962686B2 (en) * 1994-10-12 2005-11-08 California Institute Of Technology Cell-specific gene delivery vehicles
CA2160819A1 (en) * 1994-10-21 1996-04-22 Yuji Hashiguchi Diagnostic imaging agent
US6770261B2 (en) * 1995-06-02 2004-08-03 Research Corporation Technologies Magnetic resonance imaging agents for the detection of physiological agents
US5980862A (en) * 1995-06-02 1999-11-09 Research Corporation Technologies Magnetic resonance imaging agents for the detection of physiological agents
US5707605A (en) * 1995-06-02 1998-01-13 Research Corporation Technologies Magnetic resonance imaging agents for the detection of physiological agents
US6713045B1 (en) 1995-06-02 2004-03-30 Research Corporation Technologies, Inc. Targeted magnetic resonance imaging agents for the detection of physiological processes
US5804162A (en) * 1995-06-07 1998-09-08 Alliance Pharmaceutical Corp. Gas emulsions stabilized with fluorinated ethers having low Ostwald coefficients
US6106866A (en) * 1995-07-31 2000-08-22 Access Pharmaceuticals, Inc. In vivo agents comprising cationic drugs, peptides and metal chelators with acidic saccharides and glycosaminoglycans, giving improved site-selective localization, uptake mechanism, sensitivity and kinetic-spatial profiles, including tumor sites
CZ281298A3 (cs) * 1996-03-05 1999-01-13 Acusphere, Inc. Fluorované plyny v mikrokapslích jako zobrazující činidla pro ultrazvukové vyšetření
US5611344A (en) * 1996-03-05 1997-03-18 Acusphere, Inc. Microencapsulated fluorinated gases for use as imaging agents
US5837221A (en) * 1996-07-29 1998-11-17 Acusphere, Inc. Polymer-lipid microencapsulated gases for use as imaging agents
US5900228A (en) 1996-07-31 1999-05-04 California Institute Of Technology Bifunctional detection agents having a polymer covalently linked to an MRI agent and an optical dye
GB9705521D0 (en) * 1997-03-18 1997-05-07 Univ Sheffield The use of mononuclear phagocytes in the vivo imaging of hypoxic/ischaemic tissue
EP0885616A1 (de) * 1997-06-20 1998-12-23 Schering Aktiengesellschaft Verwendung von intravenösen Kontrastmitteln sowie Vorrichtungen für die Projektionsmammographie
US6713046B1 (en) 1997-10-27 2004-03-30 Research Corporation Technologies Magnetic resonance imaging agents for the delivery of therapeutic agents
AU752812B2 (en) 1997-11-17 2002-10-03 Research Corporation Technologies, Inc. Magnetic resonance imaging agents for the detection of physiological agents
DE19758118A1 (de) * 1997-12-17 1999-07-01 Schering Ag Polyrotaxane
US6113880A (en) * 1997-12-17 2000-09-05 Schering Aktiengesellschaft Polyrotaxane derivatives for x-ray and nuclear magnetic resonance imaging
US6548663B1 (en) 1998-03-31 2003-04-15 Bristol-Myers Squibb Pharma Company Benzodiazepine vitronectin receptor antagonist pharmaceuticals
US6537520B1 (en) 1998-03-31 2003-03-25 Bristol-Myers Squibb Pharma Company Pharmaceuticals for the imaging of angiogenic disorders
US6524553B2 (en) * 1998-03-31 2003-02-25 Bristol-Myers Squibb Pharma Company Quinolone vitronectin receptor antagonist pharmaceuticals
AU2371400A (en) 1998-12-18 2000-07-03 Du Pont Pharmaceuticals Company Vitronectin receptor antagonist pharmaceuticals
CA2727746A1 (en) 1998-12-18 2000-06-22 Bristol-Myers Squibb Pharma Company Quinolone vitronectin receptor antagonist pharmaceuticals
US6569402B1 (en) 1998-12-18 2003-05-27 Bristol-Myers Squibb Pharma Company Vitronectin receptor antagonist pharmaceuticals
US6511649B1 (en) * 1998-12-18 2003-01-28 Thomas D. Harris Vitronectin receptor antagonist pharmaceuticals
US6794518B1 (en) 1998-12-18 2004-09-21 Bristol-Myers Squibb Pharma Company Vitronectin receptor antagonist pharmaceuticals
US6409987B1 (en) 1999-04-07 2002-06-25 Intimax Corporation Targeted agents useful for diagnostic and therapeutic applications
HUP0202635A3 (en) * 1999-07-29 2006-03-28 Epix Medical Inc Cambridge Targeting multimeric imaging agents through multilocus binding
US6685914B1 (en) * 1999-09-13 2004-02-03 Bristol-Myers Squibb Pharma Company Macrocyclic chelants for metallopharmaceuticals
US6656448B1 (en) 2000-02-15 2003-12-02 Bristol-Myers Squibb Pharma Company Matrix metalloproteinase inhibitors
US6673333B1 (en) 2000-05-04 2004-01-06 Research Corporation Technologies, Inc. Functional MRI agents for cancer imaging
WO2001087354A2 (en) * 2000-05-17 2001-11-22 Bristol-Myers Squibb Pharma Company Use of small molecule radioligands for diagnostic imaging
BR0106717A (pt) * 2000-06-01 2002-04-16 Bristol Myers Squibb Pharma Co Compostos, composição farmacêutica e usos dos compostos de lactama inovadora
AU2001276956A1 (en) 2000-07-17 2002-01-30 California Institute Of Technology Macrocyclic mri contrast agents
JP2004509924A (ja) * 2000-09-25 2004-04-02 ザ、プロクター、エンド、ギャンブル、カンパニー Ｍｒｉ画像増強組成物
WO2002028441A2 (en) 2000-10-04 2002-04-11 California Institute Of Technology Magnetic resonance imaging agents for in vivo labeling and detection of amyloid deposits
IL145723A0 (en) * 2000-10-11 2002-07-25 Nihon Mediphysics Co Ltd Process for producing an amide compound
US6776977B2 (en) * 2001-01-09 2004-08-17 Bristol-Myers Squibb Pharma Company Polypodal chelants for metallopharmaceuticals
IL157444A0 (en) 2001-02-23 2004-03-28 Bristol Myers Squibb Pharma Co Labeled macrophase scavenger receptor antagonists and diagnostic and pharmaceutical compositions containing the same
US20030004236A1 (en) * 2001-04-20 2003-01-02 Meade Thomas J. Magnetic resonance imaging agents for detection and delivery of therapeutic agents and detection of physiological substances
US20030135108A1 (en) * 2001-05-02 2003-07-17 Silva Robin M. High throughput screening methods using magnetic resonance imaging agents
WO2002087632A1 (en) * 2001-05-02 2002-11-07 Metaprobe, Inc. High throughput screening methods using magnetic resonance imaging agents
US20090062256A1 (en) * 2001-06-01 2009-03-05 Bristol-Myers Squibb Pharma Company LACTAMS SUBSTITUTED BY CYCLIC SUCCINATES AS INHIBITORS OF Abeta PROTEIN PRODUCTION
US6797257B2 (en) * 2001-06-26 2004-09-28 The Board Of Trustees Of The University Of Illinois Paramagnetic polymerized protein microspheres and methods of preparation thereof
TWI221406B (en) * 2001-07-30 2004-10-01 Epix Medical Inc Systems and methods for targeted magnetic resonance imaging of the vascular system
JP2004537573A (ja) * 2001-08-08 2004-12-16 ブリストル−マイヤーズ・スクイブ・ファーマ・カンパニー 心臓灌流およびビトロネクチン受容体を標的とするイメージング剤の同時イメージング
US6838074B2 (en) 2001-08-08 2005-01-04 Bristol-Myers Squibb Company Simultaneous imaging of cardiac perfusion and a vitronectin receptor targeted imaging agent
US7344702B2 (en) 2004-02-13 2008-03-18 Bristol-Myers Squibb Pharma Company Contrast agents for myocardial perfusion imaging
DE10141106A1 (de) * 2001-08-22 2003-03-13 Aventis Pharma Gmbh Verwendung von Heparinoid-Derivaten zur Behandlung und Diagnose von mit Heparinoiden behandelbaren Erkrankungen
BR0307206A (pt) 2002-01-24 2004-12-21 Barnes Jewish Hospital Agentes de formação de imagem direcionados por integrina
WO2003065991A2 (en) * 2002-02-05 2003-08-14 Bristol-Myers Squibb Company N-substituted3-hydroxy-4-pyridinones and pharmaceuticals containing thereof
US20030198597A1 (en) * 2002-04-22 2003-10-23 Meade Thomas J. Novel macrocyclic activatible magnetic resonance imaging contrast agents
AU2003251436A1 (en) * 2002-07-22 2004-02-09 Bracco Imaging S.P.A. Procedures of cellular labelling with paramagnetic complexes for mri applications
US20040022857A1 (en) * 2002-07-31 2004-02-05 Uzgiris Egidijus E. Synthesis of highly conjugated polymers
WO2004064869A2 (en) * 2003-01-22 2004-08-05 The General Hospital Corporation Amyloid-binding, metal-chelating agents
ITPD20030174A1 (it) * 2003-07-31 2003-10-29 Univ Padova Coniugati polimerici per diagnostica e terapia
CA2534426A1 (en) * 2003-08-08 2005-02-17 Barnes-Jewish Hospital Emulsion particles for imaging and therapy and methods of use thereof
US20050106100A1 (en) * 2003-09-03 2005-05-19 Harris Thomas D. Compounds containing matrix metalloproteinase substrates and methods of their use
US20050136003A1 (en) * 2003-10-31 2005-06-23 Casebier David S. Novel chemical agents comprising a cardiotonic moiety and an imaging moiety and methods of their use
US20050106101A1 (en) * 2003-10-31 2005-05-19 Ajay Purohit Novel chemical agents comprising an adenosine moiety or an adenosine analog moiety and an imaging moiety and methods of their use
US7557577B2 (en) * 2003-12-08 2009-07-07 Siemens Aktiengesselschaft Water-soluble paramagnetic substance reducing the relaxation time of the coolant in an MRI system
US7485283B2 (en) * 2004-04-28 2009-02-03 Lantheus Medical Imaging Contrast agents for myocardial perfusion imaging
WO2005107818A2 (en) * 2004-04-30 2005-11-17 University Of Florida Nanoparticles and their use for multifunctional bioimaging
WO2005115105A2 (en) * 2004-05-10 2005-12-08 Northwestern University Self-immolative magnetic resonance imaging contrast agents sensitive to beta-glucuronidase
US8012457B2 (en) 2004-06-04 2011-09-06 Acusphere, Inc. Ultrasound contrast agent dosage formulation
EP1768558A4 (de) 2004-06-09 2009-11-25 Kereos Inc Lipophile derivate von chelat-monoamiden
US20060083681A1 (en) * 2004-10-18 2006-04-20 Ajay Purohit Compounds for myocardial perfusion imaging
EA011516B1 (ru) 2005-01-13 2009-04-28 Синвеншен Аг Композиционный материал и способ его изготовления
WO2006124726A2 (en) 2005-05-12 2006-11-23 The General Hospital Corporation Novel biotinylated compositions
AU2006266074A1 (en) * 2005-06-30 2007-01-11 Bristol-Myers Squibb Pharma Company Hydrazide conjugates as imaging agents
US7824659B2 (en) 2005-08-10 2010-11-02 Lantheus Medical Imaging, Inc. Methods of making radiolabeled tracers and precursors thereof
EP1937753A1 (de) * 2005-10-18 2008-07-02 Cinvention Ag Duroplastische teilchen und herstellungsverfahren dafür
WO2007070827A2 (en) * 2005-12-15 2007-06-21 Bristol-Myers Squibb Pharma Company Contrast agents for myocardium perfusion imaging
US20090317335A1 (en) * 2006-04-20 2009-12-24 Wenbin Lin Hybrid Nanomaterials as Multimodal Imaging Contrast Agents
US20070258908A1 (en) * 2006-04-27 2007-11-08 Lanza Gregory M Detection and imaging of target tissue
AU2008206953A1 (en) * 2007-01-19 2008-07-24 Cinvention Ag Porous, non-degradable implant made by powder molding
EP2126040A1 (de) * 2007-02-28 2009-12-02 Cinvention Ag Kultivierungssystem mit grosser oberfläche
US20080206862A1 (en) * 2007-02-28 2008-08-28 Cinvention Ag High surface cultivation system bag
EP2072060A1 (de) 2007-12-18 2009-06-24 Institut Curie Verfahren und Zusammensetzungen zur Herstellung und Verwendung von Toxinkonjugaten
KR101861025B1 (ko) 2008-01-08 2018-05-24 랜티우스 메디컬 이메징, 인크. 영상화 제제로서의 ｎ-알콕시아미드 접합체
PT2257315T (pt) * 2008-02-29 2020-01-27 Lantheus Medical Imaging Inc Agentes de contraste para aplicações incluindo imagiologia de perfusão
US20100029909A1 (en) * 2008-05-23 2010-02-04 Northwestern University Compositions and methods comprising magnetic resonance contrast agents
US8580231B2 (en) 2008-05-23 2013-11-12 Northwestern University Compositions and methods comprising magnetic resonance contrast agents
DE102008024976A1 (de) 2008-05-23 2009-12-17 Marvis Technologies Gmbh Medizinisches Instrument
US8293206B2 (en) 2008-05-30 2012-10-23 Siemens Medical Solutions Usa, Inc. Achievement of a high therapeutic index through molecular imaging guided targeted drug treatment
ES2617741T3 (es) 2009-04-10 2017-06-19 INSERM (Institut National de la Santé et de la Recherche Médicale) Fucoidanos como ligandos para el diagnóstico de patologías degenerativas
PT2419096T (pt) 2009-04-15 2020-02-19 Lantheus Medical Imaging Inc Estabilização de composições radiofarmacêuticas utilizando ácido ascórbico
WO2011005322A2 (en) 2009-07-08 2011-01-13 Lantheus Medical Imaging, Inc. N-alkoxyamide conjugates as imaging agents
PT2534136T (pt) 2010-02-08 2017-12-15 Lantheus Medical Imaging Inc Métodos para sintetizar agentes de imagiologia, e seus intermediários
EP2450067A1 (de) 2010-10-18 2012-05-09 MaRVis Technologies GmbH Medizinische Vorrichtung
US9272054B2 (en) 2010-12-03 2016-03-01 Institut National De La Sante Et De La Recherche Medicale (Inserm) Agents for the molecular imaging of serine-protease in human pathologies
EP2658869B1 (de) 2010-12-30 2019-06-12 INSERM (Institut National de la Santé et de la Recherche Médicale) Antigenbindende formate zur verwendung in therapeutischen behandlungen oder diagnosetests
EP2484388A1 (de) 2011-02-05 2012-08-08 MaRVis Technologies GmbH Implantierbare oder einsetzbare, mittels MRT erkennbare medizinische Vorrichtung mit einer Beschichtung, die paramagnetische Ionen umfasst, und Verfahren zu deren Herstellung
CA2852897C (en) * 2011-10-21 2016-08-16 Nagasaki University Ge adsorbent for 68ge-68ga generator
US20150337308A1 (en) 2012-04-11 2015-11-26 Chu De Bordeaux Matrix metalloproteinase 9 (mmp-9) aptamer and uses thereof
EP2692365A1 (de) 2012-08-03 2014-02-05 MaRVis Medical GmbH Implantierbare oder einsetzbare, mittels MRT erkennbare medizinische Vorrichtung mit einer Beschichtung, die paramagnetische Ionen umfasst, und Verfahren zu deren Herstellung
AU2013203000B9 (en) 2012-08-10 2017-02-02 Lantheus Medical Imaging, Inc. Compositions, methods, and systems for the synthesis and use of imaging agents
EP3441467A3 (de) 2012-08-31 2019-04-24 The General Hospital Corporation Biotinkomplexe zur behandlung und diagnose von morbus alzheimer
EP2733153A1 (de) 2012-11-15 2014-05-21 INSERM (Institut National de la Santé et de la Recherche Médicale) Verfahren zur Herstellung von Immunkonjugaten und Verwendungen davon
EP3140657A4 (de) * 2014-05-09 2017-12-13 The Arizona Board Of Regents On Behalf Of The University Of Arizona Verfahren und zusammensetzungen für oral verabreichte kontrastmittel zur mr-bildgebung
EP3541368B1 (de) 2016-11-16 2023-07-12 The United States of America, as represented by the Secretary, Department of Health and Human Services Abbildbare partikel, verfahren zur herstellung und verfahren zur verwendung davon
US11607462B2 (en) 2017-05-16 2023-03-21 Northwestern University Systems and methods for minimally-invasive assessment of toxicity-induced tissue injury
WO2021172030A1 (ja) * 2020-02-28 2021-09-02 国立大学法人九州大学 組成物、動的核偏極用組成物、高偏極化組成物、物質の高偏極化方法、高偏極化した物質およびｎｍｒ測定方法
WO2021189052A1 (en) * 2020-03-20 2021-09-23 Robert Taub Composition for radiation treatment of intracavitary or metastatic deposits of malignancy and method for treatment therewith

Family Cites Families (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2740170C2 (de) * 1977-05-17 1982-02-04 Tabushi, Iwao, Kyoto Alkylsubstituierte cyclische Tetraalkylentetramine
US4247406A (en) * 1979-04-23 1981-01-27 Widder Kenneth J Intravascularly-administrable, magnetically-localizable biodegradable carrier
US4370476A (en) * 1979-07-17 1983-01-25 Usher Thomas C Dextran polycarboxylic acids, ferric hydroxide complexes
US4957939A (en) * 1981-07-24 1990-09-18 Schering Aktiengesellschaft Sterile pharmaceutical compositions of gadolinium chelates useful enhancing NMR imaging
DE3129906C3 (de) * 1981-07-24 1996-12-19 Schering Ag Paramagnetische Komplexsalze, deren Herstellung und Mittel zur Verwendung bei der NMR-Diagnostik
US4647447A (en) * 1981-07-24 1987-03-03 Schering Aktiengesellschaft Diagnostic media
US4452773A (en) * 1982-04-05 1984-06-05 Canadian Patents And Development Limited Magnetic iron-dextran microspheres
US4432987A (en) * 1982-04-23 1984-02-21 Pfizer Inc. Crystalline benzenesulfonate salts of sultamicillin
US4472509A (en) * 1982-06-07 1984-09-18 Gansow Otto A Metal chelate conjugated monoclonal antibodies
US4731239A (en) * 1983-01-10 1988-03-15 Gordon Robert T Method for enhancing NMR imaging; and diagnostic use
NL194579C (nl) * 1983-01-21 2002-08-05 Schering Ag Diagnostisch middel.
US4423158A (en) * 1983-01-27 1983-12-27 Gelinnovation Handelsaktiebolag Ion adsorbent for metals having a coordination number greater than two
US4735796A (en) * 1983-12-08 1988-04-05 Gordon Robert T Ferromagnetic, diamagnetic or paramagnetic particles useful in the diagnosis and treatment of disease
DE3316703A1 (de) * 1983-05-04 1984-11-08 Schering AG, 1000 Berlin und 4709 Bergkamen Orales kontrastmittel fuer die kernspintomographie und dessen herstellung
GB8413849D0 (en) * 1984-05-31 1984-07-04 Amersham Int Plc Nmr contrast agents
US4639365A (en) * 1984-10-18 1987-01-27 The Board Of Regents, The University Of Texas System Gadolinium chelates as NMR contrast agents
SE465907B (sv) * 1984-11-01 1991-11-18 Nyegaard & Co As Diagnosticeringsmedel innehaallande en paramagnetisk metall
DE3577185D1 (de) * 1984-11-01 1990-05-23 Nycomed As Paramagnetische kontrastmittel fuer die anwendung in "in vivo" nmr-diagnostischen methoden und die herstellung davon.
US4735210A (en) * 1985-07-05 1988-04-05 Immunomedics, Inc. Lymphographic and organ imaging method and kit
GB8525974D0 (en) * 1985-10-22 1985-11-27 Nyegaard & Co As Chemical substance
GB8601100D0 (en) * 1986-01-17 1986-02-19 Cosmas Damian Ltd Drug delivery system
US4770183A (en) * 1986-07-03 1988-09-13 Advanced Magnetics Incorporated Biologically degradable superparamagnetic particles for use as nuclear magnetic resonance imaging agents
US4822594A (en) * 1987-01-27 1989-04-18 Gibby Wendell A Contrast enhancing agents for magnetic resonance images
US4832877A (en) * 1987-09-28 1989-05-23 Exxon Research And Engineering Company Tetranuclear sulfido-bridged complex of Cr(III) having a strongly magnetic ground state

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008003682A1 (en) * 2006-07-06 2008-01-10 Novartis Ag Non invasive method for assessing mucus clearance

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JPS63501798A (ja) 1988-07-21
CA1280364C (en) 1991-02-19
ATE90879T1 (de) 1993-07-15
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US5155215A (en) 1992-10-13
DE3688613T2 (de) 1994-01-13

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